Ohhhh! I know whats happening maybe...the site only keeps the login cookies active for 2 weeks...

Do this..when you get to the login screen, don't type anything into the login boxes, instead click 'login' a couple of times, you'll get error type messeges, and then you will see a 'keep me signed in for 2 weeks' checkbox, then login with username and pass word.

Try that and let me know if it works ;)